LOS ANGELES - "American Idol" is down to 12 finalists, and among them are all the archetypes of seasons past. There is the perky blond cowgirl, her hair now straightened and her outfits looking to be straight from the mall; the soulful crooner who channels Luther Vandross supremely; the rocker gal who has to fight against lapsing into a Janis Joplin imitation; and the budding teenybopper now stylized to attract an older audience.

In this, the seventh season of the biggest show on television, it says a lot that one of the most intriguing mysteries this year revolves around what the look will be for the show's new stage set, to be unveiled Tuesday night on Fox.

The producers of "American Idol" made much this year about having the most talented crop of contestants in a long time, and the performances so far have not proved that wrong. Nevertheless, the show seems to have settled into the ruts dug by previous years.

There are the Internet-generated "scandals," winked at and forgiven by the "Idol" producers, featuring one contestant with a past as a male stripper, and another, a young woman, whose sexually suggestive photographs have appeared online. There are, too, the questions about the "amateur" status of some of the contestants, at least one of whom previously had an album released by a major recording company.

And among the judges, Simon Cowell is still the mean one whose unvarnished opinions regularly draw boos from the crowd, and Paula Abdul still has trouble at times forming sentences.

Perhaps it is those familiarities that account for the decline in the size of the audience tuning in to the series each week. Over all, the show has once again quickly risen to the top as the most watched on television, according to Nielsen Media Research. But the 30 million viewers, on average, for each of its Tuesday and Wednesday shows make up an audience about 10 percent smaller than the 33 million who watched through the first two months of last season, and 5 percent smaller than the same period in 2006.

While hardly disastrous in a year in which most of the broadcast networks have suffered audience declines, it is worth noting that Fox was the only broadcast network whose average prime-time audience was up last fall, as compared with a year earlier. That number is still up, thanks to the very large Super Bowl audience the network enjoyed in February.

But the prospect remains that what was once the most innovative reality show on television has become, in its seventh season, perhaps one of the most predictable - if not exactly the most scripted - series on the air.

Because of that predictability, and the tight rein that Fox and the show's producers keep on the contestants, the flock of media that tracks the show's every twitter tries to make hay of whatever straws it can find. Before the season-opening audition episodes were concluded, the chatter around the show focused on a few contestants who had previously released recordings.

Carly Smithson, the Irish barkeep who lives in San Diego, was the subject of a 2002 article on the front page of The Wall Street Journal documenting how MCA Records had spent more than $2 million marketing her album. Titled "Ultimate High," it was released under her maiden name, Carly Hennessy. At the time it had sold 378 copies.

Ms. Smithson, who is one of the finalists, and Kady Malloy, who was eliminated last week and who also had produced an album, were within the rules, which state that a contestant cannot be under contract with a record company or a talent manager at the time they audition.

"I just don't think it's very important," Ms. Malloy told reporters after her elimination. "Anybody can fail at an album, and these days anybody can pretty much get a record deal too."

The producers also defended David Hernandez, the Glendale, Ariz., singer who until last fall worked as a nude dancer at a Phoenix club that serves a mostly male clientele, according to The Associated Press. (Representatives from the club, Dick's Cabaret, did not respond to telephone calls and e-mail messages seeking comment.)

In an interview with TV Guide, Ken Warwick, an executive producer of "American Idol," said: "The truth is, we're never judgmental about what people do to earn a living. They've got to put food in people's mouths. We've had strippers on the show before."

Though the producers excluded a contestant, Frenchie Davis, in Season 2 after it was revealed that she posed for topless photos that appeared on a Web site, they have allowed other contestants, including this season's finalist Ramiele Malubay, to remain in the competition after racy but clothed photos of them surfaced.

All of those topics are sidelights to the real question, of course: Who will win the competition? The show's successful formula dictates that viewers are told each week which two contestants received the least number of votes, with one being sent home. But the audience is never told which of those remaining is winning more favor with viewers each week.

Nigel Lythgoe, an executive producer, explained in an interview earlier this season that the audience would probably dwindle if it became obvious that one contestant was far ahead in the votes each week, as, he said, Carrie Underwood was in Season 4.

This season Mr. Cowell has already proclaimed that he believes that David Archuleta, the 17-year-old from Murray, Utah, is the one to beat. Mr. Cowell has previously picked favorites, as he did two years ago when he preferred Chris Daughtry over Taylor Hicks. Mr. Hicks went on to win the competition.

Now Mr. Daughtry is by far the bigger recording star, and he recently returned the favor, telling Rolling Stone magazine that he believed that "American Idol" was "lacking some credibility at this point" and is in a "state of decline."

After his comments caused an uproar, he amended them on his own Web site, daughtryofficial.com. "If you heard the whole conversation," he wrote, "you would've heard all the good things I said about the show as well."